Car covers are not the best solution and rain proof, breathable ones are expensive.
I had an unusual limit space so I made my temporary garage out of ABS plumbing pipe reinforced with 1"x3" angled boards secured with metal gate hardware. The end horizontal pieces are made of two tubes of different sizes so one fits in another so the width can be varied if needed. A regular cheap tarp fits over it. The roof is made out of 2x2 with joints of plastic that came from an inexpensive green house kit. It is strong enough to withstand the odd heavy (moisture laden) snow and while it is somewhat protected from the wind it is held down by J reinforcing rod driven into the ground. It all cost a couple hundred dollars, about the same as a cheap metal/canvas cover but it was made to size rather than the regular 10x20.
You could make a pup tent type similar thing that will just fit over the small TR7 with curvable white plumbing pipe but that stuff isn't strong enough for a heavy snow fall (already tried that).
To late now but you do need a tarp on the ground as the Tercel's exhaust system is rusted out just sitting there on the bare ground as I only drive it once in a blue moon now.
The Spitfires are covered by regular tarps but I'm not worried about paint as they need restoring.
- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT